Terminal connection for electric lamps.



R. B. BROWNLEE.

TERMINAL CONNECTION FOR ELECTRIC LAMPS.

APPLICATION FILED res. u. I914.

1,237,61 1 Patented Aug. 21, 1917.

pnrra snares are rare.

ROBERT B. BROWNLEE, OF EAST ORANGE, NEW JERSEY, ASSIGNOR T COOPER HEWITT ELECTRIC COMPANY, OF HOIBOKEN, NEW JERSEY, A CORPORATION OF NEW JERSEY.

I Specification of Letters Patent.

Patented Aug. 21, 1917.

Application filed February 11, 1914. Serial No.- 817,968.

To all whom it may concern:

Be it known that I, ROBERT B. BRowNLEE,

a citizen of the United States, and resident of East Orange, county of Essex, State of New Jersey, have invented certain new and useful Improvements in Terminal Connections for Electric Lamps, of which the following is a specification.

The present invention is designed as an improvement on certain inventions disclosed by Frederick G. Keyes in his applications numbered 811,002 and 811,003, filed in the United States Patent Office on January 8th, 1914. In said application the applicant Keyes shows and describes tungsten electric lamps provided with large filaments capable of carrying 20 or 30 or more amperes of curs rent and appearing in the form of spirals, the ends of which are attached to heavy metallic leads within the lamps. In the same application the inventor has disclosed terminal connections of a certain character between the filaments and the lead wires.

The terminal connections shown in the said applications are adapted to form permanent junctions between the parts named and have been found'to serve the purpose adequately.

The connections shown in the present applic tion may be substituted for the permanent junctions mentioned, although they are readily replaceable in case of need. The special adaptability, however, of the technical connections herein described is to use as detachable junctions, as will presently be described.

In some instances it may happen that the filament is broken or so far reduced in diameter from the spattering off of filament particles as to render its replacement necessary.

To accomplish this without taking apart the lamp, the present special mode of connecting the filament to the leads has been devised and adopted. To this end, the lamp globe may be opened up at the bottom or some views of one form of terminal connection;

Figs' 4 and 5 are similar views of another form and Figs. 6 and 7 similar views of a third form of connection.

It will be understood that the filament itself, besides being supported by the terminal connections shown is also supported at different points in its length by anchor rods,

as will be hereinafter described.

Referring to the drawings, 1 is a lamp globe within which is mounted a tungsten filament, 2, joined by terminal connections, 3, 3, to leads, 4, 4. The leads are carried up through a diaphragm, 5, which may be of porcelain or of aluminum, but is here shown as a metallic diaphragm, preferably aluminum. This diaphragm is supported near the mouth of a tubular portion, 6 of the globe, 1, the object being to shut off rom the tubular extension and from the lamp seals near the top thereof all unnecessary heat. The leads, 4, 4, after passing up through the diaphragm, 5, are shown as being provided with sockets, 7, 7, suitably secured thereto and having any convenient depth. Into these sockets extend copper leads, 8, 8, which form mechanically a part of the seals of the lamp. The leads 8, 8 pass through platinum tubes, 9, 9, stea dying the main conducting portion of the lamp seal. On the outer ends of the tubes 9, 9 are placed iron caps, 10, 10, which are welded to the tubes 9, 9 and the rods 8, 8 by means of an oxy-acetylene flame. The external leads may be copper wires, 11, 11, fused or soldered to the caps, 10, 10, as shown.

The seals are made within a reentrant portion ofthe tubular extension, 6, whereby the danger of fracture from mechanical causes is reduced. The tubes 9, 9 are sealed within saidrentrant portion. The entire interior of the lamp is then sealed off fromexposure to the external air and a thoroughly efliclent mode of scaling is provided. To join the leads 4, 4 and the leads 8, 8, set screws, 12, 12, may be provided as one convenient means. The leads 4, 4, where they pass through openings in the diaphragm 5,

ported in the disk and insulated therefrom and from the leads 4, 4. The said anchor rods may be of iron, but are preferably provided with tips, 16, 16, of tungsten wire sealed to the iron rod and bent around at its outer end so as to surround completely or partially portions of the tungsten spiral 2.

I have found in practice that a long spiral of heavy tungsten wire has a tendency to sag and, for this reason, it is of advantage to spread the spiralat the points where the sagging is likely to take place as shown at 17. This prevents the coils of the spiral from coming into contact with each other at the sagging points. Similar spreading portions may be assumed at the: lower part of every sagging portion shown'in Fig. 1.

As indicated above, one element of the present invention is that of providing detachable end connections between the filament 2 and the leads 4, 4. The filament having been prepared and drawn or, spirally wound in the manner illustrated in Fig. 1, the detachable terminals may be selectively applied to the ends of the filament and the lower ends of the lead, as will now be described.

Referring to Figs. 2 and 3, the lower end of one of the leads 4: is represented as being screw threaded and secured to a block or plate 18 of metal.

The plate, 18, is provided with an opening through which passes, in the form of junction shown in Figs. 2 and 3, a cylindrical rod, 19, having a head or shoulder, 20, on its inner end and an annular groove, 21, near its opposite end. The spiral, 2, is wound around a part of the rod 19 lying between the head 20 and the plate 18. The spiral having been applied as indicated to the rod 19, a tight connection between the spiral and the plate 18 is secured by clamping a wire, 22, having projecting ends, 23, within the groove 21 by means of nippers or some other suitable tool, thus bringing about the close connection desired.

In Figs. 4 and 5 the opening in the plate 18 is wedge shaped, and the part of the rod 19 which passes through the said opening is split and capable of being forced out at its ends into intimate contact outside ofthe plate 18 by means of a wedge or other suitable tool.

In Figs. 6 and 7 I show the rod 19 as being formed into the shape of a bar, 24, through which a pin, 25, is adapted to be passed for completing the connection between the parts most directly concerned.

As stated this may be a form of connection designed for use for all purposes; but it is found to be particularly useful in making terminal connections through the bota metallic plate and a headedcylinder passing through the said plate, in combination with means for compressing a portion of the spiral bet-ween the head and the outer side of the plate.

2. In a metallic filament lamp, a spiral of filament material of tungsten, terminal junctions therefor, said junctions including a metallic plate and a. headed cylinder passing'through the said plate,-in combination with means for compressing a portion of the spiral between the head and the plate, said means consisting of a compressible split ring lying in an annular groove on the opposite side of the plate from the head.

Signed at New York, in thecounty of New York and State of New York, this 10th day of February, A. D. 191 1.

ROBERT B. BROWVNLEE.

\Vitnsses WM. H. CAPEL, THos. H. BRowN. 

